<template>
	<view class="wxy-code">
		<!-- 支付宝小程序是id、其他平台是canvas-id -->
		<!-- #ifndef MP-ALIPAY -->
		<canvas class="wxy-code-canvas" :canvas-id="cid" :style="{ width: cpSize + 'px', height: cpSize + 'px' }" />
		<!-- #endif -->
		<!-- #ifdef MP-ALIPAY -->
		<canvas class="wxy-code-canvas" :id="cid" :width="cpSize" :height="cpSize" />
		<!-- #endif -->
		<image v-show="show" :src="result" :style="{ width: cpSize + 'px', height: cpSize + 'px' }" />
	</view>
</template>

<script>
import QRCode from './qrcode.js';
let qrcode;
export default {
	props: {
		cid: {
			type: String,
			default: 'wxy-code-canvas'
		},
		size: {
			type: Number,
			default: 200
		},
		unit: {
			type: String,
			default: 'upx'
		},
		show: {
			type: Boolean,
			default: true
		},
		val: {
			type: String,
			default: ''
		},
		background: {
			type: String,
			default: '#ffffff'
		},
		foreground: {
			type: String,
			default: '#000000'
		},
		pdground: {
			type: String,
			default: '#000000'
		},
		icon: {
			type: String,
			default: ''
		},
		iconSize: {
			type: Number,
			default: 40
		},
		lv: {
			type: Number,
			default: 3
		},
		onval: {
			type: Boolean,
			default: false
		},
		loadMake: {
			type: Boolean,
			default: false
		},
		usingComponents: {
			type: Boolean,
			default: false
		},
		showLoading: {
			type: Boolean,
			default: true
		},
		loadingText: {
			type: String,
			default: '二维码生成中'
		}
	},
	data() {
		return {
			result: ''
		};
	},
	methods: {
		makeCode: function() {
			let that = this;
			if (!that._empty(that.val)) {
				qrcode = new QRCode({
					context: that, // 上下文环境
					canvasId: that.cid, // canvas-id
					usingComponents: that.usingComponents, // 是否是自定义组件
					showLoading: that.showLoading, // 是否显示loading
					loadingText: that.loadingText, // loading文字
					text: that.val, // 生成内容
					size: that.cpSize, // 二维码大小
					background: that.background, // 背景色
					foreground: that.foreground, // 前景色
					pdground: that.pdground, // 定位角点颜色
					correctLevel: that.lv, // 容错级别
					image: that.icon, // 二维码图标
					imageSize: that.iconSize, // 二维码图标大小
					cbResult: function(res) {
						// 生成二维码的回调
						that._result(res);
					}
				});
			} else {
				uni.showToast({
					title: '二维码内容不能为空',
					icon: 'none',
					duration: 1500
				});
			}
		},
		clearCode() {
			this._result('');
			qrcode.clear();
		},
		saveCode() {
			let that = this;
			if (that.result != '') {
				uni.saveImageToPhotosAlbum({
					filePath: that.result,
					success: function() {
						uni.showToast({
							title: '二维码保存成功',
							icon: 'success',
							duration: 2000
						});
					}
				});
			}
		},
		_result(res) {
			this.result = res;
			this.$emit('result', res);
		},
		_empty(v) {
			let tp = typeof v,
				rt = false;
			if (tp == 'number' && String(v) == '') {
				rt = true;
			} else if (tp == 'undefined') {
				rt = true;
			} else if (tp == 'object') {
				if (JSON.stringify(v) == '{}' || JSON.stringify(v) == '[]' || v == null) rt = true;
			} else if (tp == 'string') {
				if (v == '' || v == 'undefined' || v == 'null' || v == '{}' || v == '[]') rt = true;
			} else if (tp == 'function') {
				rt = false;
			}
			return rt;
		}
	},
	watch: {
		size: function(n, o) {
			if (n != o && !this._empty(n)) {
				this.cSize = n;
				if (!this._empty(this.val)) {
					setTimeout(() => {
						this.makeCode();
					}, 100);
				}
			}
		},
		val: function(n, o) {
			if (this.onval && n != o && !this._empty(n)) {
				setTimeout(() => {
					this.makeCode();
				}, 0);
			}
		}
	},
	computed: {
		cpSize() {
			if (this.unit == 'upx') return uni.upx2px(this.size);
			return this.size;
		}
	},
	mounted: function() {
		if (this.loadMake && !this._empty(this.val)) {
			setTimeout(() => {
				this.makeCode();
			}, 0);
		}
	}
};
</script>
<style lang="scss" scoped>
.wxy-code {
	position: relative;
}
.wxy-code-canvas {
	position: fixed;
	top: -99999upx;
	left: -99999upx;
	z-index: -99999;
}
</style>
